Forced air warmers may be used in both hypo- and hyperthermia treatments to help to regulate the temperature of a patient. These devices typically comprise an air heating device provided inside a chamber, a flexible hose in air communication with the chamber and a blower arranged to transport heated air from the chamber through the hose into a forced air warming blanket. Typically, the forced air warming blanket comprises an air permeable surface facing the patient.
A key requirement for forced air warmers is that the temperature of the air being provided to the forced air warming blanket can be measured reliably and accurately. The temperature of the heated air would ideally be measured at the forced air warming blanket. However, this is not typically possible. Accordingly, the temperature of the heated air must typically be measured elsewhere.
One possible solution is to measure the temperature of the heated air at an outlet of the chamber. However, temperature measurements made at the outlet of the chamber have been found to be subject to variable errors, and are therefore unreliable. Another possible solution is to measure the temperature of the heated air at an outlet of the flexible hose. However, this requires the hose to include a temperature sensor and wiring which is expensive and is subject to breakage with repeated use of the hose.
Accordingly, the invention addresses the technical problem of how to reliably, accurately and inexpensively measure the temperature of heated air provided by a forced air warmer.